Download FIX Dictionaries
Download FIX 5.0 SP2 and FIXT 1.1 XML specifications (ZIP)
Rate Limits
The FIX API enforces a rate limit of 150 messages per second per session. This limit applies to all inbound messages from the client to the exchange, across all participants.Firm, User and Account Identifiers
The Polymarket US exposes two FIX gateways to participants; an order management gateway, and a second gateway to receive market data. Additional drop-copy sessions can be provided upon request. Note that should the Exchange offer direct market access (DMA) to their underlying customer, then each DMA customer should have their own dedicated pair of FIX gateways. An example FIX session configuration is shown below. Note the network details and Sender/TargetCompID (in red) will be provided by the exchange operator.Example QuickFIX session configuration
[DEFAULT] ConnectionType=initiator SocketConnectHost=12.12.12.12 SocketConnectPort=13001 BeginString=FIXT.1.1 DefaultApplVerID=9 SenderCompID=SENDERCOMP1 [SESSION] TargetCompID=EXCHANGECOMPID
The Polymarket US also validates individual users (traders) using SenderSubID (50), and customer accounts using Account (1) which are validated on order entry. Please contact the exchange operator to allocate these codes.
Symbology
Polymarket US uses a simple string identifier to instruments trading on the platform, which is required to identify instruments in the API using Symbol (55). There is currently no support to identify instruments using any other common identifiers such as CUSIP, ISIN or Bloomberg code. A list of instruments on the platform can be retrieved using the SecurityListRequest [x] message.Instrument States
Instruments follow the primary lifecycle: PENDING → OPEN → CLOSED → EXPIRED → TERMINATED. Instruments may also be SUSPENDED or HALTED during their lifecycle.Primary State Flow
Exception States
Other Possible States
FIX Notation
Please note the following presentation notes which apply to message definitions and FIX examples throughout this document.- FIX tag/value pairs are delimited within a TCP connection using the SOH (ascii character 1) character. Since this is a non-printable character, in this document we use the | character instead, and pad each pair with spaces to make them easier to use.
- Components are blocks of FIX tags which appear frequently in the specification (e.g. header and footers which appear on every FIX message). They are defined centrally for convenience and then referenced throughout the document using <> notation.
- Repeating groups of FIX tags appear in various messages. The depth of a repeating group is indicated using the → marker in FIX message definitions.
- References to individual FIX fields (or “tags”) are presented in italic font, with the tag number following the tag name. For example HeartBtInt (108).